Disulfide derivatives useful for treating allergic diseases

ABSTRACT

Novel disulfide derivatives useful for preventing or treating allergic diseases of the eye, nose, skin, ear, gastrointestinal tract, airways or lung and preventing or treating manifestations of systemic mastocytosis are disclosed. The disulfide derivatives act as mast cell stabilizers.

This application claims priority from co-pending U.S. ProvisionalApplication, U.S. Serial No. 60/205,827, filed May 19, 2000, amd is adivisional application of U.S. Ser. No. 09/841,859 filed Apr. 25, 2001.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to novel disulfide derivatives useful fortreating allergic diseases.

2. Description of the Related Art

Antihistamines and mast cell stabilizers are two types of drugscurrently used topically to treat allergic diseases. Antihistamine drugsare used to interrupt the allergic effects that histamine causes afterit has been released from a mast cell. Many topical antihistamine drugsare marketed. For example, emedastine difumarate and levocabastinehydrochloride are available for ocular allergies (see Ophthalmic DrugFacts 1999, Facts and Comparisons, St. Louis, Mo., pp. 59-80).

Mast cell stabilizers prevent mast cells from “degranulating” orreleasing histamine and other components or “mediators” during anallergic reaction. Examples of ophthalmic drugs marketed as mast cellstabilizers include olopatadine (see U.S. Pat. No. 5,641,805) andcromolyn sodium.

U.S. Pat. No. 4,705,805 discloses certain disulfide derivatives that areuseful as anti-thrombotic agents. The disulfide derivatives suppressblood platelet aggregation. The '705 patent does not disclose the use ofdisulfide derivatives in the topical treatment of allergic diseases ofthe eye or nose.

SUMMARY OF THE INVENTION

The present invention provides methods for preventing or treatingallergic diseases of the eye, nose, skin, ear, gastrointestinal tract,airways or lung. The methods may also be used to treat manifestations ofsystemic mastocytosis. The methods of the present invention comprisetopically or systemically administering to a patient a novel mast cellstabilizing disulfide derivative of the formula

wherein

X=—NHC(=O)NH—R;

R=H; (un)substituted phenyl; (un)substituted benzyl; or C₁-C₈ alkyl oralkenyl, optionally substituted with or terminated by OH, OR², NR³R⁴;C₄-C₇ cycloalkyl, (un)substituted aryl, or (un)substituted 5-7 memberedheterocyclic ring; where optional substituents are selected from thegroup consisting of C₁-C₆ alkyl or alkoxy; halogen; OH; CN; CF₃; NO₂;and CO₂R²;

R²=C₁-C₃ alkyl; and

R³ and R⁴ are independently H; benzyl; C₁-C₈ alkyl or alkenyl; C₄-C₇cycloalkyl; (un)substituted aryl; or (un)substituted 5-7 memberedheterocyclic ring; wherein optional substituents are selected from thegroup consisting of C₁-C₆ alkyl or alkoxy; halogen; OH; CN; CF₃; NO₂;and CO₂R₂.

The present invention is also directed toward topically or systemicallyadministrable compositions for treating or preventing allergic diseasesof the eye, nose, skin, ear, gastrointestinal tract, airways or lung andtreating or preventing manifestations of systemic mastocytosis, whereinthe compositions comprise a disulfide derivative of formula (I).

DETAILED DESCRIPTION OF THE INVENTION

The disulfide derivatives of formula (I) can be made as described inScheme 1.

The appropriate isocyanate is added to a stirring solution of the bisamino-disulfide in a solvent such as tetrahydrofuran or methylenechloride at a temperature between −20° C. and 30° C. An organic basesuch as triethylamine, or pyridine is added after the reaction mixturehas stirred for 5 to 30 minutes and the reaction is stirred for 6 to 48hr. The disulfides can then be isolated using standard, knownprocedures.

Preferred compounds of formula (I) are those having the X substituentsin the ortho position and wherein R=C₁-C₈ alkyl or alkenyl, optionallysubstituted with or terminated by OH, OR², NR³R⁴; C₄-C₇ cycloalkyl,(un)substituted aryl, or (un)substituted 5-7 membered heterocyclic ring;where optional substituents are selected from the group consisting ofC₁-C₆ alkyl or alkoxy; halogen; OH; CN; CF₃; NO₂; and CO₂R². Mostpreferred are compounds wherein R=C₁-C₅ alkyl or alkenyl, optionallysubstituted with or terminated by OH, OR², NR³R⁴; C₄-C₇ cycloalkyl,(un)substituted aryl, or (un)substituted 5-7 membered heterocyclic ring;where optional substituents are selected from the group consisting ofC₁-C₆ alkyl or alkoxy; halogen; OH; CN; CF₃; NO₂; and CO₂R².

Compounds of formula (I) may be administered topically (i.e., local,organ-specific delivery) or systemically by means of conventionaltopical or systemic formulations, such as solutions, suspensions or gelsfor the eye and ear; nasal sprays or mists for the nose; metered doseinhalers for the lung; solutions, gels, creams or lotions for the skin;oral dosage forms including tablets or syrups for the gastrointestinaltract; and parenteral dosage forms including injectable formulations.The concentration of the compound of formula (I) in the formulations ofthe present invention will depend on the selected route ofadministration and dosage form. The concentration of the compound offormula (I) in topically administrable formulations will generally beabout 0.00001 to 5 wt. %. For systemically administrable dosage forms,the concentration of the compound of formula (I) will generally rangefrom about 10 mg to 1000 mg.

The preferred formulation for topical ophthalmic administration is asolution intended to be administered as eye drops. For solutionsintended for topical administration to the eye, the concentration of thecompound of formula (I) is preferably 0.0001 to 0.2 wt. %, and mostpreferably from about 0.0001 to 0.01 wt. %. The topical compositions ofthe present invention are prepared according to conventional techniquesand contain conventional excipients in addition to one or more compoundsof formula (I). A general method of preparing eye drop compositions isdescribed below:

One or more compounds of formula (I) and a tonicity-adjusting agent areadded to sterilized purified water and if desired or required, one ormore excipients. The tonicity-adjusting agent is present in an amountsufficient to cause the final composition to have an ophthalmicallyacceptable osmolality (generally about 150-450 mOsm, preferably 250-350mOsm).

Conventional excipients include preservatives, buffering agents,chelating agents or stabilizers, viscosity-enhancing agents and others.The chosen ingredients are mixed until homogeneous. After the solutionis mixed, pH is adjusted (typically with NaOH or HCl) to be within arange suitable for topical ophthalmic use, preferably within the rangeof 4.5 to 8.

Many ophthalmically acceptable excipients are known, including, forexample, sodium chloride, mannitol, glycerin or the like as atonicity-adjusting agent; benzalkonium chloride, polyquaternium-1 or thelike as a preservative; sodium hydrogenphosphate, sodiumdihydrogenphosphate, boric acid or the like as a buffering agent;edetate disodium or the like as a chelating agent or stabilizer;polyvinyl alcohol, polyvinyl pyrrolidone, polyacrylic acid,polysaccharide or the like as a viscosity-enhancing agent; and sodiumhydroxide, hydrochloric acid or the like as a pH controller.

If required or desired, other drugs can be combined with the disulfidederivatives of formula (I), including, but not limited to,antihistaminic agents, anti-inflammatory agents (steroidal andnon-steroidal), and decongestants. Suitable antihistaminic agentsinclude emedastine, mapinastine, epinastine, levocabastine, loratadine,desloratadine, ketotifen, azelastine, cetirazine, and fexofenadine. Thepreferred antihistaminic agent for ophthalmic use is emedastine, whichis generally included in topically administrable compositions at aconcentration of 0.001-0.1 wt. %, preferably 0.05 wt. %. Suitableanti-inflammatory agents includemometasone, fluticasone, dexamethasone,prednisolone, hydrocortisone, rimexolone and loteprednol. Suitabledecongestants include oxymetazoline, naphazoline, tetrahydrozoline,xylometazoline, propylhexedrine, ethylnorepinephrine, pseudoephedrine,and phenylpropanolamine.

According to the present invention, the disulfide derivatives of formula(I) are useful for preventing and treating ophthalmic allergicdisorders, including allergic conjunctivitis, vernal conjunctivitis,vernal keratoconjunctivitis, and giant papillary conjunctivitis; nasalallergic disorders, including allergic rhinitis and sinusitis; oticallergic disorders, including eustachian tube itching; allergicdisorders of the upper and lower airways, including intrinsic andextrinsic asthma; allergic disorders of the skin, including dermatitis,eczema and urticaria; allergic disorders of the gastrointestinal tract,including systemic anaphylaxis resulting from ingestion of allergen andiatrogenic anaphylaxis caused by contrast agents used during diagnosticimaging procedures; and manifestations of systemic mastocytosisincluding hypotension.

The following examples are intended to be illustrative but not limiting.

EXAMPLE 1

Topical Ophthalmic Solution Formulation

Ingredient Concentration (wt. %) Compound of formula (I) 0.0001 to 0.2Dibasic Sodium Phosphate (Anhydrous) 0.5 Sodium Chloride 0.65Benzalkonium Chloride 0.01 NaOH/HCl q.s. pH 6-8 Purified Water q.s.100  

EXAMPLE 2

Topical Ophthalmic Gel Formulation

Ingredient Concentration (wt. %) Compound of formula (I) 0.0001 to 0.2Carbopol 974 P 0.8 Edetate Disodium 0.01 Polysorbate 80 0.05Benzalkonium Chloride 0.01 NaOH/HCl q.s. pH 6-8 Water for iniection q.s.100  

EXAMPLE 3

Synthesis of bis-[2-(3-allylurea)-phenyl)]-disulfide (II)

To a stirred solution of 2-aminophenyl disulfide (1.5 g, 6 mmol) in 10ml of THF, was added allyl isocyanate (1.1 ml, 12 mmol). After stirringat room temperature for 5 min, 1 ml of triethylamine was added. Theresulting mixture was stirred and refluxed for 18 hr. After cooling, thesolvent was evaporated and the solids were filtered off. The filtratewas washed with 5% of HCI, saturated NaHCO₃ and saturated NaCl and thendried over MgSO₄. Concentration under reduced pressure andchromatography of the residue on silica gel, eluting with 30% of ethylacetate in hexane to 60% of ethyl acetate in hexane gave 0.31 g of II asa white solid.

¹H NMR (CDCl₃) δ8.14-7.90 (m, 4H), 7.33-6.86 (m, 8H), 5.95-5.79 (m, 2H),5.25-5.07 (m, 4H), 3.33-3.31 (m, 4H). ¹³C NMR (CDCl₃) δ154.94 (C=O),140.28 (C), 135.95 (CH), 133.51 (CH), 130.04 (CH), 124.91 (C), 122.45(CH), 121.46 (CH), 114.91 (CH₂), 41.93 (CH₂). Analysis calculated forC₂₀H₂₂O₂N₄S₂ requires: C, 57.95; H, 5.35; N, 13.52%. Found: C, 57.91; H,5.39; N, 13.46%.

EXAMPLE 4

Mast Cell Activity

Preparation of Cell Suspension

Methods detailing preparation of monodispersed HCTMC and mediatorrelease studies with these cells have been described (U.S. Pat. No.5,360,720 and Miller et al, Ocular Immunology and Inflammation,4(1):39-49 (1996)). Briefly, human conjunctival tissue mast cells wereisolated from post-mortem tissue donors obtained within 8 hours of deathby various eye banks and transported in Dexsol® corneal preservationmedium, or equivalent. Tissues were enzymatically digested by repeatedexposure (30 min. at 37° C.) to collagenase and hyaluronidase (2× with200 U each/gram tissue, then 2-4× with 2000 U each/gram tissue) inTyrode's buffer containing 0.1% gelatin. (Tyrode's buffer (in mM): 137NaCl, 2.7 KCl, 0.35 NaH₂PO4, 1.8 CaCl_(2,) 0.98 MgCl₂, 11.9 NaHCO₃, and5.5 glucose). Each digestion mixture was filtered over Nitex® cloth (100μm mesh, Tetko, Briarcliff Manor, N.Y.) and washed with an equal volumeof buffer. Filtrates were centrifuged at 825×g (7 min). Pellets wereresuspended in buffer then combined for enrichment over a 1.058 g/LPercoll® cushion. The enriched pellet was washed, resuspended insupplemented RPMI 1640 medium and incubated at 37° C. to equilibrate.

Histamine Release Studies

Cells were harvested from the culture plate and counted for viability(trypan blue exclusion) and mast cell number (toluidine blue O). Mastcells (5000/tube; 1 mL final volume) were challenged (37° C.) for 15 minwith goat-anti-human IgE (10 μg/mL) following treatment (15 minutes; 37°C.) with test drug or Tyrode's buffer. Total and non-specific releasecontrols were exposed to 0.1% Triton X-100 and goat IgG (10 μg/mL),respectively. The reaction was terminated by centrifugation (500×g, 4°C., 10 min). Supernatants were stored at −20° C. until analyzed forhistamine content by RIA (Beckman Coulter, Chicago, Ill.).

Preparation of Test Drug Solutions

All test drugs were made to solution immediately prior to use. Each wasdissolved in DMSO at 10 mM or greater concentration and then diluted inTyrode's buffer containing 0.1% gelatin over the concentration forevaluation.

Data Analysis

Inhibition of histamine release was determined by direct comparison ofwith anti-IgE challenged mast cells using Dunnett's t-test (Dunnett, “Amultiple comparison procedure for comparing treatments with a control”,J. Amer. Stat. Assoc. (1955), 50:1096-1121). An IC50 value (theconcentration at which the test compound inhibits histamine release at alevel of 50% compared to the positive control) was determined by4-parameter logistic fitting using the Levenburg-Marquardt algorithm orby linear regression. The results are reported in Table 1.

TABLE 1

COMPOUND NO. T X MOLSTRUCTURE IC50 (nM) 1 S—S

314 10 175 278 [194]

The data shown in Table 1 indicate that the compounds of formula (I)potently inhibit histamine release from human conjunctival mast cells inan in vitro model of allergic conjunctivitis.

EXAMPLE 5

Topical Ophthalmic Solution Formulation

Ingredient Concentration (wt. %) Compound of formula (I) 0.0001 to 0.2Emedastine  0.001 to 0.1 Dibasic Sodium Phosphate (Anhydrous) 0.5 SodiumChloride 0.65 Benzalkonium Chloride 0.01 NaOH/HCl q.s. pH 6-8 PurifiedWater q.s. 100  

The invention has been described by reference to certain preferredembodiments; however, it should be understood that it may be embodied inother specific forms or variations thereof without departing from itsspirit or essential characteristics. The embodiments described above aretherefore considered to be illustrative in all respects and notrestrictive, the scope of the invention being indicated by the appendedclaims rather than by the foregoing description.

What is claimed is:
 1. A topically or locally administrablepharmaceutical composition for treating allergic diseases of the eye,nose, skin, ear or lung comprising a tonicity-adjusting agent in anamount sufficient to cause the composition to have an osmolality of150-450 mOsm, a pharmaceutically acceptable preservative and a disulfidederivative of the formula

wherein X=—NHC(═O)NH—R; R=H; (un)substituted phenyl; (un)substitutedbenzyl; or C₁-C₈ alkyl or alkenyl, optionally substituted with orterminated by OH, OR², NR³R⁴; C₄-C₇ cycloalkyl, (un)substituted aryl, or(un)substituted 5-7 membered heterocyclic ring; where optionalsubstituents are selected from the group consisting of C₁-C₆ alkyl oralkoxy; halogen; OH; CN; CF₃; NO₂; and CO₂R²; R²=C₁-C₃ alkyl; and R³ andR⁴ are independently H; benzyl; C₁-C₈ alkyl or alkenyl; C₄-C₇cycloalkyl; (un)substituted aryl; or (un)substituted 5-7 memberedheterocyclic ring; wherein optional substituents are selected from thegroup consisting of C₁-C₆ alkyl or alkoxy; halogen; OH; CN; CF₃; NO₂;and CO₂R².
 2. The pharmaceutical composition of claim 1 wherein the Xsubstituents are in the ortho position and wherein R=C₁-C₈ alkyl oralkenyl, optionally substituted with or terminated by OH, OR², NR³R⁴;C₄-C₇ cycloalkyl, (un)substituted aryl, or (un)substituted 5-7 memberedheterocyclic ring; where optional substituents are selected from thegroup consisting of C₁-C₆ alkyl or alkoxy; halogen; OH; CN; CF₃; NO₂;and CO₂R².
 3. The pharmaceutical composition of claim 6 wherein R=C₁-C₅alkyl or alkenyl, optionally substituted with or terminated by OH, OR²,NR¹R⁴; C₄-C₇ cycloalkyl, (un)substituted aryl, or (un)substituted 5-7membered heterocyclic ring; where optional substituents are selectedfrom the group consisting of C₁-C₆ alkyl or alkoxy; halogen; OH; CN;CF₃; NO₂; and CO₂R².
 4. The pharmaceutical composition of claim 3wherein X is —NHC(═O)NH—CH₂—CH═CH₂.
 5. The pharmaceutical composition ofclaim 1 wherein the disulfide derivative is present in an amount fromabout 0.00001 to 5 wt. %.
 6. The pharmaceutical composition of claim 6wherein the disulfide derivative is present in an amount from about0.0001 to 0.2 wt. %.
 7. The pharmaceutical composition of claim whereinthe disulfide derivative is present in an amount from about 0.0001 to0.01 wt. %.